Sid: The first migrants arrived near the Croatian frontier on Wednesday, potentially carving out a new route through Europe after Hungary sealed its borders.

The group of 30-40 mostly Syrian or Afghan migrants arrived at the Serbian border town of Sid early in the morning. They had travelled by bus from the Macedonian border at Presevo, 500 kilometres to the south.

Among the mixed group of men, women and children of all ages was Amadou, 35, from Mauritania in western Africa.

"We heard that Hungary was closed so the police told us we should come this way," he said.

"We don't know what we should do now. Do we have to catch a boat?"

He was pleased to hear there was no water to cross and it was only about 10 kilometres to the border. He was also surprised to hear the group was thought to be the first to attempt this route into northern Europe.

Until this week, the vast majority of migrants and refugees travelled up from Greece, through Macedonia and Serbia into Hungary.

But Hungary sealed its southern border on Monday as part of a wider crackdown on migrants entering the country.

The new route takes the migrants to Croatia, from where they will have to travel through Slovenia to get to northern Europe.

Like others at the bus station in Sid, Amadou had never heard of Croatia and did not know it was in the European Union.

"We want to go anywhere there is peace," he said. "There is so much suffering in Mauritania, so many problems for our family, no work."

He and his friend looked very thin, exhausted and slightly afraid.

Many were trying to get some rest after the long bus ride. A man huddled on the ground in a sleeping bag suddenly turned to ask: "What country are we in?"

He hoped to reach France and wanted to know the cost of the bus ticket. They paid EUR 35 (USD 40) to get to Sid from Presevo.

Mohammed Qadir, 20, from Pakistan had never heard of Croatia before. He just wants to work.

"There is no money, no food, no electricity where I am from. I have to earn some money for my brothers and sisters."